Method of treating sewage.



A. PRIESTMAN.

METHOD OF TREATING SEWAGE.

APPLICATION FILED MAR. 14, 191 1 Patented Dec. 9, 1913.

2 SHEETS-SHEET 1.

Fla. 3

WWW

A. PRIESTMAN. METHOD OF TREATING SEWAGE.

APPLICATION FILED MAR.14, 1911.

Patented Dec. 9, 1913.

2 SHEETS-SHEET 2.

UFFHJE ALBERT newsman, or rnmanntrma, PENNSYLVANIA.

METHQD '5 TREATING SEWAGE.

i hsosss.

Application filed March 14,

f0 all whom it may concern:

Be it lillOWllAtllliliiI; ALBERT PRIESTMAN,

asubject of the King'of lfingland, ands resident of Germantown, in the cityand county of Philadelphia, State'of- Pennsyl- Vania, have: invented an Improvement in Methods of Treating Sewage, of which the following is a is ecifioation.'-

It is well knownthat whileit is possible, under favorable Conditions, to oxidize organic matter in solution with great, if not explosive, rapidity, comparatively long periods of time are requirediorthe treatment in contact' with bacteria of the matter in suspension;

It is-the object of my invention to precipitate the solid matterand to remove-the precipitated sludge-automatically at deter- 'mined intervals-with a minimum quantity of water. Such removal ofthe sludge may be effected in volumes proportional to the volume of sewagebeing treated, andat such intervals asmay be desired; forexample,

that-amount of sludge ma-y'be automatically 26 removed in a period of twenty four hours which is precipitated in that period from the" inflowing sewage being: treated. The sludge thus removed isdischarged, preferably before putrefa'ctive processes have bedome active, and a further object of my invention is to subject this'sludge to further treatment-in a second tank or tanks in which putrefaction takes place," discharging the sludge automatically and at determined intervals in small quantities after putrcfactive Q processes have-= been active, so that the mat- "ter finallydischarged upon the sludge bed or' elsewhere will be free from offensive s- 1 I prefer that the quantities of sludge discharged from 'the second tank after putre faction has become activeshall be approxinihtely equal to the-quantities supplied to it, i3 6. discharged from: the first or precipitatingtank. The discharge of the sludge from the tanks maybe regulated by any suitable automatic, timed devices; but in the preferred form itis controlled by the overflow of the sewage from the precipitating' tank. The discharge of the sludge may thus bc'regulated to take place at fixed {intervals in relation to the flow of the sewage throughthe apparatus. The period of time during which the valves remain open 55 at each operation may also be regulated, au-

tomatically, so that they will remain open-l specification 01' Letters Patent.

PatentcolDec. 29,1913.

1911. Serial no. 614,311.

for a predetermined period in relation to the flow from each tank.

In the drawings: Figure 1 is a plan view of a sewage disposal apparatusembodying the invention; Fig. 2 is a longitudinal vertical sectional view of the same on the line A--A of Fig. 1; Fig; 3 is a'similar view on the line BB; and Fig. 4 is a longitudinal vertical sectional. view illustrating an apparatus embodying theinvention in another -form.

tcierring first to thelorrn of apparatus shown in Figs. 13: dis a settling-tank to which sewage is supplied atthe top through a pipe 3. This tank is provided at the bottom with. an outlet f which is controlled by a valve g. from the outlet f, through which the sludge is discharged. This discharge-pipe 72 may lead to any tank, bed, apparatus, or place for the further treatment or'final disposal of the sludge. In the apparatus shown in Figs. 1-3it leads to the top'oiv a second tank ml, in which putrefactive action takes place. The tank is also providgd at the bottom with an outlet f controlled by a valve 9 leading to a pipe it discharging to the sludge-bed z. c is adischarge-pipeor-conduit from the top of the tank d. In this form of the apparatus, as shown, the valves g, g which control the outlets for the sludge to the dischargepipes h, h are controlled automatically by the conditions in a tank or reservoir a into which the overflow of the sewage is discharged from the top or" the settling tank (Z by the pipe'or conduit 6. The valves shown are of the hinged flap-type opening upwardly, and are connected by chains k, is

with the floating bells m, m respectively,

which are operated from the air-bells Mn in the tank or reservoir 0 through the airpipes 0, 0. The air-bells m, m are provided respectively with the valved air-vents 7), 79'. c is a siphon by which the contents of the tank or reservoir (1 are discharged into the chamber Z), whence they pass out through the pipe s; V

The operation of this apparatus is as follows: The sewage enters the tank (Z- through the pipe 8, and after it has accumulated therein (the valye being closed), the surface liquid flows oil through the pipe or conduit c into the tank orreservoir a. When the liquid in the tank a has attained a sufl'lfililt lev l to forc enough air through-tho boll pipe 0 into the hosting ball his a discharge pipe leadingtom of the tank (Z is discharged through the outlet f into the pipe 72. In the apparatus shown the end of the air-pipe 0- Which en ters the air-bell m is provided with a U bend 0 which forms a liquid-seal, so that the bell m and valve 9 will not be operated until the level in the tank a is sutlicient to produce enough pressure in the bell n to force the water-seal 0 and admit to the bell m a charge of air which lifts it and opens the valve 9. The opening of the valve 9 thus depends primarily upon the level of the liquid in the reservoir a, and as this reservoir is supplied by the overflow of the sewage from the tank (Z, it follows that I the intervals at which the valve ,7 will be opened will be regulated according to the [low of sewage to the apparatus; and by the regulation of the supply to the tank (I, or to the tank a, the intervals at which the valvey will be opened may be controlled. The closing of the valve y is controlled by the vent p, which permits the air introduced through the pipe 0 to escape, so that as the air escapes the bell 'm may fall and close the valve y llltrllFQCtlVB of the levels in the tanks 11 and a. This enables the valve 9 to be kept open for short periods at long intervals, so that only the accumulation of comparatively dense sludge in the bottom of the settling-tank y; will be discharged.

In practice, as the sewage enters the tank (Z, the heavier matter in suspension will remain in the settling-tank (Z while only the t c .nparatively clear liquid will pass oil through the discharge pipe or conduit 6 into the reservoir (1. There will, however, be no operation of the valve g, until such a level has been. reached in the reservoir a as will provide the hydrostatic head required to force the liquid-seal in the pipe '0 and lift the bell m. The return of the bell and the closing of the valve g are however controlled by the vent p, and may be regulated by the adjustment of the valve in the vent to permit the valve g to remain open tor a very short interval of time, only sutticient to etlect the discharge of the dense sludge at the bottom of the tank (Z. By a proper adjustment of the vent 79 the valve may be allowed to remain open for a predetermined period in relation to the flow from the tank, so that an equal quantity of sludge will be discharged each time. Exactly the same operation takes place in' the tank. rZ, it' it be used. The sludge from the tank (Z enters the tank d at the top and accumulates therein until such time as vthe hydrostatic head in the reservoir a through the bell of and pipe 0' forces the seal 0 and operates the air-bell m and valve 7'. The closing of the valve 9' is controlled, just as in the case of the valve 9, by the adjustment of the valve in the vent p. The valve g is opened at intervals correspondin opined, and the vent 10 may be adjusted to permit the valve 9 to remain open for the same periodas the valve '9 remains open, consequently the quantities of sludge discharged froin the tank d after putrefa'ctive processes have become active will be the same as the quantities fed to the tank cl from the precipitating tank (Z.

lVhenever the liquid in the reservoir a reaches sulficient height to operate the siphon c it passes off through the chamber 6 and discharge-pipe s. This discharge of the liquid from the reservoir a does not," however, ailect the liquid in the settling tanks (Z, d.

m are stops in the upper part of the tanks (Z, Z to support the bells m, m when the level of the liquid falls upon the opening of the valves 9, g.

In the apparatus described the periodic opening of the valve in the settling-tank or tanks is dependent upon the supply of the sewage to the tanks, being controlled by the level of the overflow of the surface liquid from them. This is not however necessary to the invention, and in the apparatus shown in Fig. l the valve 9 is controlled by means independent of the supply of sewage to the tank (I. In this apparatus the tank at with its out-let f, valve 9 and discharge-pipe h with those at which the valve 9 is 4 are the same as in the apparatus shown in Figs. 1*3. In this case, however, a set tling tank only is shown and this discharges directly to the sludge-bed i. The valve 9 is connected by achain or-cable 7.1 running over guides k k with a suspended vessel t open at the top and provided at the bottom with a valved outlet t discharging into a tank 24. The cable 12 is provided with a counterweight to which normally balances the vessel t and permits the valve 9 to remain closed. a is an elevated chamber connected with the tank why a pipe a in which is a circulating pump Z). n is an air-bell in the chamber a, from which a water-sealed pipe 0 leads with its discharge end in position to discharge into theopen top of the suspended vessel 25.

Sullicient' liquid is present in the tank u to operate the apparatus. Normally the weight w counter-balances the vessel 2? and. permits the valve 9 to remain closed. The pump b withdraws liquid from the tank u and supplies it to the chamber a, and when the hydrostatic head in the chamber a acting through the air-bell n is sufficient to force the liquid seal in the pipe 0*, liquid will be discharged from the pipe 0 into the open top of the vessel t, and, when the weight of the liquid in the vessel 6 is sufiicicnt to overcome the Wei ht of the valve 9 and its counterweight w,t e valve y, will be I valve and its counterweight.

made-ac opened and sludge will be discharged from the bottom of the tank (Z. The valve 9 will remain open until the discharge of the liquid-through the pipe t into the tank u reduces the weight of the vessel t and its contained liquid below the weight of the The rate of this discharge, and consequently the period that the valve g will remain open, may be regulated by the adjustment of the valve 2 in the discharge'pipe t. The period at which the valve will be operated may be regulated by valves a? and 0 in the pipes a and 0 respectively. The pump Z) may be operated in any co venient manner, as by a water-wheel 03 connected with the pump by belting w and driven by the incoming sewage, or, preferably, by the filtrate from the apparatus.

In this application I do not claim the apparatus for treating sewage which is herein described and shown, as the same forms the subject matter of my application Ser. No. 701,853, filed June 5, 1912, a division of this application.

What I claim is as follows: 1. The herein described method of treat ing sewage to precipitate and remove sludge, which consists in allowing the denser part of the sewage to remain for comparatively long periods in a settling-tank to precipitate the solid matter in suspension, discharging the denser portions of the sludge from the bottom of said portion of the sewage-in relatively small quantities at intervals in relation to the flow of the sewage to or from the apparatus, and supplying fresh sewage to the top of such portion.

2. The herein described method of treating sewage to precipitate and remove sludge, which consists in allowing the denser part of the sewage to remain for comparatively long periods in a settling-tank to precipitate the solid matter in suspension, discharging the denser portions of the sludge from the bottom of said portion of the sewage in relatively small uniform quantities at ular intervals in relation to the How of the sewage to or from the apparatus, and sup plying fresh sewage to the top of such portion.

3. The herein described method of treating sewage toprecipitate and remove sludge, which consists in allowing the denser part of the sewage to remain for comparatively long periods in a settling-tank to precipitate the solid matter in suspension, dischar ing the denser portions of the sludge from the bottom of said portion of the sewage in relatively small quantities for equal periods at regular intervals in relation to the flow of the sewage to or from the apparatus, and supplying fresh sewage to the top of such portion.

4. The herein described method of treating sewage, which consists in supplying the sewage to a settling-tank at the top, discharging the denser portions of the sludge in relatively small quantities at intervals from the lower portion of the body of liquid in said tank, and controlling said discharge by the overflow of the sewage from said tank.

5. The herein described method of treat ing sewage, which consists in allowing the sewage to remain for comparatively long periods in a settling-tank to precipitate the solid matter in suspension, discharging the denser portions of the sludge in relatively small quantities and at intervals from the lower portion of the body of liquid into the top of a second tank, allowing said sludge to remain for comparatively long periods in said second tank, discharging the denser portions in relatively small quantities and at intervals from the lower portion of the sludge in said second tank, and supplying fresh sewage to the upper portion of the liquid in the first tank.

6. The herein described method of treating sewage, which consists in allowing the sewage to remain for comparatively long periods in a tank to precipitate the solid matter in suspension, discharging the denser portions of the sludge from the lower portion of the body of liquid in said tank in relatively small quantities and at intervals into the top of a second tank, and discharging the matter from the bottom of the second tank in relatively small quantities and at intervals after putrefaction has been active.

7. The herein described method of treating sewage, which consists in allowing the. sewage to remain for comparatively 1on periods in a tank to precipitate the solid matter in suspension, discharging the denser portions of the sludge from the lower portions of the body of liquid in said tank, at intervals in relatively small quantities and before putret'active processes are active, into a second tank, allowing the sludge to remain in said second tank until putrefactive processes have become active in the lower portion thereof, and discharging said lower portion at intervals in relatively small quantities.

8. The herein described method oi treating sewage, which consists in allowing the sewage to remain for comparatively lon periods in a tank'to precipitate the solid matter in suspension, discharging the denser portionsof the sludge from the lower por tions of the body of liquid in said tank, at intervals in relatively small quantities and before putrefactive processes are active, into a second tank, allowing the sludge to remain in said second tank until putrefactive processes have become active in the lower portion thereof, and discharging said lower portion at intervals in relatively small quantities approximately equal to the quantities supplied from the first tank to said second tank.

9. The herein described method of treat ing sewage, which consists in allowing the sewage to remain for comparatively long periods in a tank to precipitate the solid matter in suspension, discharging the denser portions of the sludge from the lower portions of the body of liquid in said tank at intervals in relatively small quantities and before putreiiactive processes are active, into a second tank, allowing the sludge to remain in said second tank until pntretactire processes have become active in the lower portion thereof, discharging said lower portion at intervals in. relatively small quantiln. and controlling the discharge from the first tank to the second tank by the overllow o1 sewage from the first tank.

10. The herein described method of treating sewage, which consists in allowing the sewage to remain for coi'nparatircly longperiods in a tank to precipitate the solid matter in suspension, discharging the denser portions of the sludge from the lower portions of the body oi liquid in said tank, at intervals in relatively small quantities and before putrc'factivc processes are active, into a second tank, allowing the sludge to remain in said second tank until putret'active proc-- esses have become active in the lower portion thereof, discharging said lower portion at intervals in relatively small quantities, and controlling the discharge from both tanks by the overflow of the sewage from the first tank.

11. The herein described method of treating sewage, which consists in allowing the sewage to remain for comparatively long periods in a settling-tank to precipitate the solid matter in suspension, discharging the denser portions of the sludge in relativelysmall quantities and at intervals from the lower portion of the body of liquid into the top oi? a second tank, allowing said sludge to remain for comparatively long periods in said second tank, (lischarging the denser portions in relatively small quantities and at intervals from the lower portion of the sludge in said second tank, and supplying fresh sewage to the upper portion of the liquid in the first tank, and autonnitically controlling the discharge of the sludge from both settling-tanks by the overflow of the sewage from the first tank.

in testimony of which invent-ion I hereunto set my hand.

M. Gr. EGAN. 

